Waste disposal units are used to comminute putrescible organic waste into a slurry or pulp for transport away from the point at which comminution occurs. In domestic situations, the waste disposal unit may be located adjacent to a kitchen sink area where food is prepared.
Larger scale waste disposal units may also be used in industrial applications such as in restaurants, canteens, hotel kitchens, fruit/vegetable shops, food courts, hospitals, fast food outlets, clubs, bakeries and supermarkets, Such units are often used to reduce the waste to a slurry and water is added as a delivery means so as to transport the slurry down a waste line to a waste outlet, for example a sewerage system. The resultant product transported to the waste outlet is substantially a liquid.
After treatment in the waste disposal unit, the waste pulp is usually eliminated by disposal in the sewerage system, thereby increasing the amount of waste that that will require treatment through the sewer system. Furthermore, there is no automated control over the amount of water required to flush the putrescible organic waste during comminution and hence there is a strong possibility that an excess amount of water may be used in the comminution process. This of course leads to wastage of scheme water which is environmentally undesirable and expensive.
A further disadvantage in disposing putrescible organic waste in sewerage systems is that a potential energy source is not utilised. Biological waste can be digested in anaerobic reactors to produce ‘biogas’. Biogas is about 60-65% methane and can be used as a fuel source to generate electricity. The residual slurry product may then be further processed for use as a fertilizer. At the time of writing, this technology has been implemented by Biotechnische Abfallverwertung GmbH & Co KG (BTA) in 22 plants worldwide. A problem for biogas producers such as BTA is that the biological waste feed collected for the biogas digester can be contaminated with inorganic materials such as plastics, cardboard and ceramics due to the inadvertent inclusion at the point of collection of the putrescible organic waste material.
Any discussion of documents, publications, acts, devices, substances, articles, materials or the like which is included in the present specification has been done so for the sole purpose so as to provide a contextual basis for the present invention. Any such discussions are not to be understood as admission of subject matter which forms the prior art base, or any part of the common general knowledge of the relevant technical field in relation to the technical field of the present invention to which it extended at the priority date or dates of the present invention.